Wireless data communications devices, such as cellular telephones and wireless LAN transceivers, are in widespread use worldwide. There is increasing need for higher data transmission rates and the support for the ever growing number of users and data traffic. Moreover, the rapidly decreasing physical size and power consumption of mobile devices compel them to become ever more highly integrated, e.g., configured with internal antennas and fully sealed construction. All of these factors, however, increase the complexity of these wireless devices. Manufacturers, vendors and users therefore have a greater need for improved testing of such devices. Notably, the inherent complexity of wireless data communication devices makes them particularly problematic to test due to the difficulty of accessing their internally integrated antennas, isolating the wireless devices from external interference, and controlling the coupling between the wireless device and the test equipment. For example, actual open-air radio frequency (RF) environments contain high levels of uncontrollable noise and interference, which have significant impact on device performance. The lack of controllability and test repeatability also makes it difficult or impossible to automate the testing of such wireless devices. Consequently, there is great appeal for manufacturers and users to be able to test these devices in a repeatable fashion that excludes the interference and variability of real RF environments and also controls the degree of wireless coupling between the wireless device and the test equipment device. This also enables the tests to be conducted in an automated fashion, or by personnel not highly skilled in RF channel characteristics.
Some methods of isolating and coupling to wireless communications devices include the use of anechoic and reverberation chambers, shielded enclosures of various sizes, cabled connections to device antenna connectors or antennas, the utilization of antenna ranges, and/or the DUT operation in open air environments. All of these methods exhibit one or more deficiencies when considering the requirements of modern wireless devices. Anechoic and reverberation chambers are very expensive, bulky and fixed at one location due to their large size and weight. Shielded enclosures offer limited portability but are still relatively expensive and heavy, and suffer from repeatability issues. Further, small shielded enclosures present many problems when dealing with wireless device systems. Tests involving cabled connections to the wireless DUT are simple and offer very high repeatability and low cost, but are unfortunately impractical or impossible with modern highly integrated compact devices such as cellular telephones. Outdoor antenna ranges are expensive and difficult to find, due to their real estate requirements, and further have problems when dealing with wireless transmission. Open air environments are highly variable, nearly impossible to reproduce, and present significant challenges with repeatability and controllability.
Accordingly, there is a need for a flexible planar antenna device for wireless device testing.